The invention relates to an exhaust-gas turbocharger for an internal combustion engine, in particular for an internal combustion engine of a utility vehicle, with an exhaust gas turbocharger having an exhaust gas turbine arranged in an exhaust tract and a turbine-driven compressor arranged in an intake duct of the internal combustion engine and to a method for determining the air mass supplied by the compressor to the internal combustion engine.
Knowledge of the air mass supplied to an internal combustion engine is needed in passenger vehicles and utility vehicles as an engine-related measured variable for example for exhaust-gas recirculation control. In passenger vehicle engines, hot film air mass sensors (HFM) are used as standard for measuring the air mass sucked in. For reasons of durability, of sensor drift and interface definition with respect to the vehicle, it is generally not possible to integrate an HFM sensor of said type in utility vehicle engines. Furthermore, HFM sensors of said type are conventionally sensitive to pulsations and are extremely susceptible to contamination.
There is therefore a demand for a device or measure, which can also be advantageously used in utility vehicles for measuring an air mass flow to an internal combustion engine.
In this connection, DE 15 76 278 A, for example, discloses a fuel injection system for internal combustion engine, which fuel injection system has a freely adjustable throttle flap in an air intake duct. Provided upstream of the throttle flap are a dynamic pressure measuring device and a further throttle element. The dynamic pressure measuring device comprises a dynamic pressure probe for measuring the total pressure in the air intake duct, and a measurement bore in the duct wall for measuring the static pressure in the air intake duct, with the further throttle element being positioned in the air intake duct between the dynamic pressure probe and the measurement bore. Fuel is supplied to the engine as a function of the differential pressure which is determined from the total pressure and from the static pressure in the air intake duct.
Furthermore, Patent Abstracts of Japan JP 63-090621 A discloses an exhaust-gas turbocharger for an internal combustion engine including a compressor upstream of which an air mass sensor is arranged. No further details are given in the abstract regarding the type and mode of operation of the air mass sensor which is used.
DE 14 28 043 A describes a turbocompressor for an internal combustion engine which has, arranged between the impeller blades, a dynamic pressure probe for measuring a characteristic flow angle.
It is an object of the present invention to provide an exhaust-gas turbocharger for an internal combustion engine, in particular an internal combustion engine of a utility vehicle, which permits simple and reliable measurement of the air mass sucked in by the internal combustion engine, which measured variable can be used for example for exhaust-gas recirculation control. It is a further object of the invention to provide a method for determining the air mass sucked in by an internal combustion engine.